diff options
Diffstat (limited to 'nuttx/libc/fixedmath/lib_b16cos.c')
-rw-r--r-- | nuttx/libc/fixedmath/lib_b16cos.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/nuttx/libc/fixedmath/lib_b16cos.c b/nuttx/libc/fixedmath/lib_b16cos.c new file mode 100644 index 000000000..0ebe48262 --- /dev/null +++ b/nuttx/libc/fixedmath/lib_b16cos.c @@ -0,0 +1,64 @@ +/**************************************************************************** + * libc/fixedmath/lib_b16cos.c + * + * Copyright (C) 2007, 2008, 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <fixedmath.h> + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Global Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: b16cos + ****************************************************************************/ + +b16_t b16cos(b16_t rad) +{ + /* Compute cosine: sin(rad + PI/2) = cos(rad) */ + + rad += b16HALFPI; + if (rad > b16PI) + { + rad -= b16TWOPI; + } + return b16sin(rad); +} |